99% of people here haven't driven their Forester at those speeds.

I think the problem comes up because the good comes down and meets the headlights. There is no seal there to prevent air from coming in, generating some lift. Also, the air intake for the turbo is drawing air up along the inside of the hood, which likely creates some lift. Also, since the hood is aluminum, it is lighter than a steel hood would be.

I also experience the issue, mainly when passing an oncoming semi or other large profile vehicle. The blast of wind you catch behind the truck causes my hood to shake.

It is a little concerning, but I think it is normal. The hood latch seems to be solid enough to keep it latched.

 

I notice something similar driving on the highway looked like the hood was moving up and down. Stopped and checked to see if maybe I did not close properly found nothing. Wife says I was imagining it.

 

Josh's explanation is very plausible. I think that's a fairly low speed to be causing hood flutter, though... given that the Forester is sold in markets around the world that have much higher speed limits than the US. My SG XT didn't exhibit this type of problem until well into the triple digit speeds (hood scoop starts to vibrate around 130 mph). That being said, you could probably install hood pins to alleviate/eliminate the problem.

 

Had this issue with my crosstrek as well. This happens because there is some give on the hood. If you push down on the hood you'll see that it goes down a millimeter or two. On slightly uneven roads on the highway you'll be able to see a slight shaking of the hood.


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Same. Actually noticed it a few weeks back going 80mph on a high wind day. I'll be looking into ways to reduce this, but with the air channeling to the TMIC, I doubt much can be done. Didn't hear any rattle, thankfully.

 

One thing I believe would help us to add a rubber of foam seal on the front edge of the hood to close the gap over the headlights.

 

if you have ever been in an STI or a turbo Subaru with a hood scoop the hood tends to wiggle around a lot. On my STI and Miata the hood has a fiberglass exo skeletal frame that is used to lighten it up. The way the air flows under the hood now, as has been said can create some lift. I have been faster than the mentioned speeds and have not really noticed the hood dancing around but it should not come undone from the latch.

 

To be fair, if you're going any faster than the speeds mentioned above, you'd better be focused the blacktop and not the hood.

 

Thank you guys for all responses, now I see this is not a failure just a Subaru thing like small vibrations at cold start from the engine. Anyway I am happy with my car

 

If you really really really fell like messing with it you can adjust the rubber hood stops by turning them clockwise to lower. They are two rubber cylinders located above the headlights on the radiator support beam. Be sure to adjust them one turn at a time, and both of them evenly. Then close the hood slowly and carefully to ensure you don't lower it too far. It can contact the grill or headlights if too far down. Mine is presently is fairly low and does not "lift" at those speeds. It does however have a small amount of vibration in the middle at the edge nearest to the windshield at those speeds, which is normal metal flexing.

 

I experience this all the time when semi trucks go past me on two lane highways. I thought it was because of my custom grill not sealing tight, good to know it's everyone though! Someone should install some bonnet pins and see if that helps :icon_cool:

 

I don't notice this on my Forester but on my 2012 Outback it flecks big time at almost any speed. It was the first thing my Son said on his first test drive.


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I had this problem as well. I adjusted the stops about 1 turn up. Fixed it.

I used to see it waving around a tiny bit when you hit potholes in the road expansion joints. etc.

now its 90% better.

It used to drive me nuts.. I would be driving and see it vibrating all over.

 

The stops adjustment help line up the fender and hood profile. The latch adjustment should take out any play in the hood latch.

Older muscle cars used a rubber/foam seal between the front hood edge and the radiator support to direct the most air thru the radiators.

The hood scoop is just catching the air and lifting the center of the hood.

 

minor technical point - air flowing under the hood does not generate lift. If anything, it would do the opposite. Think about Bernoulli's principle. Faster flow means decreasing pressure.

Flutter is no doubt due to varying air speed above and below the hood. Any change in the relative speed of the two will change the pressure. If the change is big enough, you'll see the flutter.

 

then why has so many hoods flown up and broke a many a windshield?

Mainly we were talking about the air induction system under the hood, because while Subaru eliminated the hood scoop they instituted a plastic air induction thing right under the hood to get air flow to the tmic. I have seen my hood float around a little but it was nothing that scared me, the STI I had would do a lot more than the Forester does.

Whoever said hood pins, they will not keep your hood from floating around either. I use to have some on a carbon fiber hood for a Honda.

 

Not only does air go under the hood to get to the TMIC, but it comes in the grille and is turned almost 90 degrees up into the part attached to the hood. The air turning like that definitely causes the air to push up on the hood.

IMO the main issue is air going in the gap between the headlight housings and the hood. When I pass a semi on a 2 lane highway, especially in Texas where both vehicles are going 75+ MPH, the corner of the hood lifts up while the latch is holding the center down.

The hood looks like the wings of a Boeing 787, which curve up under load, with the fuselage being the hood latch.

 

While I'm not doubting anything anyone has said in this thread.. in my particular case a little more preload at the latch at least dampened out the vibrations. Of course I don't have the XT hood either so that isnt exactly the same problem.

I do suggest trying to tighten the hood slightly, with either adjustment.

 

I'm curious, but would adding some mass to the outer hood skin, with something like dynomat, help?

If you had an XT, then you'd have to remove the air channeling parts to get to the outer skin, but if that's where the flex is most noticeable, then maybe that would help? Especially if it was overlapped with the inner hood panel/framing.

 

Sorry to revive an old thread but my hood has done this from day one. Fluttering at high (60+ mph) speeds. I have tryed adjusting the little rubber stopper deals, with no effect other then to twist the hood so the panel gaps are uneven from one side to the other. It’s really starting to bug me... thinking about hood pins, don’t want to cut holes though...

Am I missing something? I feel like I should be able to fix this with the stoppers by finding the right position so that when latched they are compressed enough to hold the whole thing in tension... but I can’t.

Are pins the only way to stop the flutter?


also the hood seems to fit better on the passenger side then on the drivers... maybe because it’s flexy and only one side has a air shock...?

 

Same issue

I have this same issue. Anyone have a good solution yet?

I also have seen this from day one in my 2018 XT and mostly on the driver's side. I bought this expensive vehicle specifically so I could easily go 70-80+ on my boring commute to work :wink2: and I really hate seeing the hood movement.

 

I have this same issue. Anyone have a good solution yet?

I also have seen this from day one in my 2018 XT and mostly on the driver's side. I bought this expensive vehicle specifically so I could easily go 70-80+ on my boring commute to work :wink2: and I really hate seeing the hood movement.

I have gotten to the point where I don’t notice it as much/ it doesn’t bother me as much... still doing it though like every day at least twice.... likely b/c I’m at 80+ at least once per commute.